With the rapid development of technology and rapid industrialization in recent years, the discharge of untreated industrial wastewater has seriously exceeded the standard, which has damaged the ecological environment and endangered human health. Organic synthetic dyes are widely used in the textile and printing industries. Dyes are generally biotoxic and carcinogenic, and are difficult to completely degrade by microorganisms in the environment. Among them, azo dyes are the most difficult to remove, because their highly substituted aromatic ring structure is extremely stable. Therefore, it is extremely urgent to find efficient, fast and low-cost treatment of azo dyes.
Since Honda et al. used TiO2 electrode to photohydrogenate to produce hydrogen in 1972, research on materials based on semiconductor photocatalysts has developed rapidly. A large number of semiconductor photocatalysts, such as zinc oxide, antimony phosphate, antimony oxide, antimony carbonate, and ferric oxide, have been studied to degrade dyes, but the degradation time is generally long, about 2 h, due to the rapid electron-hole pairing recombination and low utilization of visible light.